The subject application relates to document scanning, and more particularly to calibrating a scanner in order to facilitate uniformity in scanned page contrast, brightness, etc. For instance, a scanner can be coupled to a printer or other xerographic device and calibrated to scan pages that pass through the scanner.
Conventional scanner systems employ calibration techniques to attempt to ensure that constant black and constant white scanned images have constant values across multiple pages. The lamp on a scanner typically changes during a warm-up period, which may run minutes to tens of minutes long. The difference in illumination can be on the order of 1.5%, and so in a typical scanning operation may be immaterial, particularly if the scanner is calibrated at the start of a sequence of scans.
Using a scanner as a surrogate for a spectrophotometer leads to much tighter requirements, which can be addressed by leaving the lamp on long enough for the illumination to stabilize. Another approach is to leave the lamp on at all times while a printer is operating. However, either of these approaches lead to additional issues with power consumption and lamp life.
Accordingly, there is an unmet need for systems and/or methods that facilitate overcoming the aforementioned deficiencies.